1. Field of the Invention
The present invention relates to heavy-duty processing and power-generating plants and has specific reference to anti-vibration mountings for shock- or vibration-producing machinery.
2. Description of the Prior Art
The impact loads of significant magnitude which are set up by operating shock- or vibration-producing machinery and are sustained by their foundations cause rapid foundation failure.
Moreover, spreading through the soil to the foundations of adjacent buildings such loads bring about their non-uniform settlement leading to gradual deterioration.
The reconditioning of damaged foundations is an intricate, lasting and coastly operation.
Known in the art is an anti-vibration mounting for die-forging hammers comprising an inertial block and isolators in the form of springs and dampers. The anvil block of the hammer rests on the inertial block, a wooden or rubber pad being interposed therebetween, and the isolators support the inertial block, being interposed between the foundation and the block (see, e.g., book "Vibraizolyatsii shtampovachnykh molotov", by I. V. Klimov, V. P. Koshelev, V. S. Nosov, Moscow "Mashinostroenie" Publishers, 1979, pp. 49-53, in Russian).
The impact loads come on the inertial block and are smoothed out by the springs and dampers located under the inertial block. But the inertial block itself has no protection against vibration, and therefore deteriorates rapidly.
To renew an anti-vibration mounting which is in bad repair, the hammer must be taken apart, the damaged inertial block, springs, dampers removed and replaced by new ones. This is a time- and money-consuming job.
Modern practice dispenses with the inertial block in shock- or vibration-producing machinery and places isolators and dampers directly under the machine.
There is known an anti-vibration mounting of forging hammers comprising leaf springs which are located in the pit directly below the anvil block and rest on supports placed on the foundation. Resilient pads are interposed between the supports and the foundation, and the base of the anvil block is provided with recesses into which the straps clamping the leaf springs (see, e.g., book "Vibroizolyatsia shtampovochnykh molotov" by I. V. Klimov, V. P. Koshelev, V. S. Nosov, Moscow, "Machinostroenie Publishers, 1979, pp.75-76, in Russian).
The known anti-vibration mounting is the prototype of the invention.
In the known anti-vibration mounting referred to hereinabove, a number of leaf springs rest with their ends on a common support which is a flat plate. These springs differ in their behaviour-for different are their dimensions, coefficients of friction, etc.--and interact with each other in operation through the common support, bringing about additional loads detrimental to their condition.
A failure of some of the springs causes the centre where the anti-vibration mounting is supported to displace out of true with the centre of gravity of the hammer. As a result, this begins to rock and imposes additional loads on the springs. All in all, the performance and reliability of the hammer are impaired.
The rocking of the machine is eliminated by renewing the damaged springs. To that end the machine must be jacked up--a job sometimes inviting many technical difficulties.
Clearances between ends of leaf springs and a flat support may get stopped with scale. This will shift the points of support of the springs involved away from their ends. The stiffness of these springs will change and the support will tend to displace from under the springs. The centre-of-gravity location of the hammer as a whole will get out of true with the result that the reliability and durability of the hammer will be impaired.